1 /*
2 * http://burtleburtle.net/bob/c/lookup3.c
3 */
4
5 /*
6 * ----------------------------------------------------------------------------
7 * lookup3.c, by Bob Jenkins, May 2006, Public Domain.
8 *
9 * These are functions for producing 32-bit hashes for hash table lookup.
10 * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
11 * are externally useful functions. Routines to test the hash are included
12 * if SELF_TEST is defined. You can use this free for any purpose. It's in
13 * the public domain. It has no warranty.
14 *
15 * You probably want to use hashlittle(). hashlittle() and hashbig()
16 * hash byte arrays. hashlittle() is is faster than hashbig() on
17 * little-endian machines. Intel and AMD are little-endian machines.
18 * On second thought, you probably want hashlittle2(), which is identical to
19 * hashlittle() except it returns two 32-bit hashes for the price of one.
20 * You could implement hashbig2() if you wanted but I haven't bothered here.
21 *
22 * If you want to find a hash of, say, exactly 7 integers, do
23 * a = i1; b = i2; c = i3;
24 * mix(a,b,c);
25 * a += i4; b += i5; c += i6;
26 * mix(a,b,c);
27 * a += i7;
28 * final(a,b,c);
29 * then use c as the hash value. If you have a variable length array of
30 * 4-byte integers to hash, use hashword(). If you have a byte array (like
31 * a character string), use hashlittle(). If you have several byte arrays, or
32 * a mix of things, see the comments above hashlittle().
33 *
34 * Why is this so big? I read 12 bytes at a time into 3 4-byte integers,
35 * then mix those integers. This is fast (you can do a lot more thorough
36 * mixing with 12*3 instructions on 3 integers than you can with 3 instructions
37 * on 1 byte), but shoehorning those bytes into integers efficiently is messy.
38 * ----------------------------------------------------------------------------
39 */
40 #define SELF_TEST 0
41
42 #if SK_LITTLE_ENDIAN
43 # define HASH_LITTLE_ENDIAN 1
44 # define HASH_BIG_ENDIAN 0
45 #elif SK_BIG_ENDIAN
46 # define HASH_LITTLE_ENDIAN 0
47 # define HASH_BIG_ENDIAN 1
48 #else
49 # define HASH_LITTLE_ENDIAN 0
50 # define HASH_BIG_ENDIAN 0
51 #endif
52
53 #define hashsize(n) ((uint32_t)1<<(n))
54 #define hashmask(n) (hashsize(n)-1)
55 #define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
56
57 /*
58 * ----------------------------------------------------------------------------
59 * mix -- mix 3 32-bit values reversibly.
60 *
61 * This is reversible, so any information in (a,b,c) before mix() is
62 * still in (a,b,c) after mix().
63 *
64 * If four pairs of (a,b,c) inputs are run through mix(), or through
65 * mix() in reverse, there are at least 32 bits of the output that
66 * are sometimes the same for one pair and different for another pair.
67 * This was tested for:
68 * * pairs that differed by one bit, by two bits, in any combination
69 * of top bits of (a,b,c), or in any combination of bottom bits of
70 * (a,b,c).
71 * * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
72 * the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
73 * is commonly produced by subtraction) look like a single 1-bit
74 * difference.
75 * * the base values were pseudorandom, all zero but one bit set, or
76 * all zero plus a counter that starts at zero.
77 *
78 * Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
79 * satisfy this are
80 * 4 6 8 16 19 4
81 * 9 15 3 18 27 15
82 * 14 9 3 7 17 3
83 * Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
84 * for "differ" defined as + with a one-bit base and a two-bit delta. I
85 * used http://burtleburtle.net/bob/hash/avalanche.html to choose
86 * the operations, constants, and arrangements of the variables.
87 *
88 * This does not achieve avalanche. There are input bits of (a,b,c)
89 * that fail to affect some output bits of (a,b,c), especially of a. The
90 * most thoroughly mixed value is c, but it doesn't really even achieve
91 * avalanche in c.
92 *
93 * This allows some parallelism. Read-after-writes are good at doubling
94 * the number of bits affected, so the goal of mixing pulls in the opposite
95 * direction as the goal of parallelism. I did what I could. Rotates
96 * seem to cost as much as shifts on every machine I could lay my hands
97 * on, and rotates are much kinder to the top and bottom bits, so I used
98 * rotates.
99 * ----------------------------------------------------------------------------
100 */
101 #define mix(a,b,c) \
102 { \
103 a -= c; a ^= rot(c, 4); c += b; \
104 b -= a; b ^= rot(a, 6); a += c; \
105 c -= b; c ^= rot(b, 8); b += a; \
106 a -= c; a ^= rot(c,16); c += b; \
107 b -= a; b ^= rot(a,19); a += c; \
108 c -= b; c ^= rot(b, 4); b += a; \
109 }
110
111 /*
112 * ----------------------------------------------------------------------------
113 * final -- final mixing of 3 32-bit values (a,b,c) into c
114 *
115 * Pairs of (a,b,c) values differing in only a few bits will usually
116 * produce values of c that look totally different. This was tested for
117 * * pairs that differed by one bit, by two bits, in any combination
118 * of top bits of (a,b,c), or in any combination of bottom bits of
119 * (a,b,c).
120 * * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
121 * the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
122 * is commonly produced by subtraction) look like a single 1-bit
123 * difference.
124 * * the base values were pseudorandom, all zero but one bit set, or
125 * all zero plus a counter that starts at zero.
126 *
127 * These constants passed:
128 * 14 11 25 16 4 14 24
129 * 12 14 25 16 4 14 24
130 * and these came close:
131 * 4 8 15 26 3 22 24
132 * 10 8 15 26 3 22 24
133 * 11 8 15 26 3 22 24
134 * ----------------------------------------------------------------------------
135 */
136 #define final(a,b,c) \
137 { \
138 c ^= b; c -= rot(b,14); \
139 a ^= c; a -= rot(c,11); \
140 b ^= a; b -= rot(a,25); \
141 c ^= b; c -= rot(b,16); \
142 a ^= c; a -= rot(c,4); \
143 b ^= a; b -= rot(a,14); \
144 c ^= b; c -= rot(b,24); \
145 }
146
147 /*
148 * --------------------------------------------------------------------
149 * This works on all machines. To be useful, it requires
150 * -- that the key be an array of uint32_t's, and
151 * -- that the length be the number of uint32_t's in the key
152 *
153 * The function hashword() is identical to hashlittle() on little-endian
154 * machines, and identical to hashbig() on big-endian machines,
155 * except that the length has to be measured in uint32_ts rather than in
156 * bytes. hashlittle() is more complicated than hashword() only because
157 * hashlittle() has to dance around fitting the key bytes into registers.
158 * --------------------------------------------------------------------
159 */
hashword(const uint32_t * k,size_t length,uint32_t initval)160 uint32_t hashword(
161 const uint32_t *k, /* the key, an array of uint32_t values */
162 size_t length, /* the length of the key, in uint32_ts */
163 uint32_t initval) /* the previous hash, or an arbitrary value */
164 {
165 uint32_t a,b,c;
166
167 /* Set up the internal state */
168 a = b = c = 0xdeadbeef + (((uint32_t)length)<<2) + initval;
169
170 /* handle most of the key */
171 while (length > 3)
172 {
173 a += k[0];
174 b += k[1];
175 c += k[2];
176 mix(a,b,c);
177 length -= 3;
178 k += 3;
179 }
180
181 /* handle the last 3 uint32_t's */
182 switch(length) /* all the case statements fall through */
183 {
184 case 3 : c+=k[2]; /* fall through */
185 case 2 : b+=k[1]; /* fall through */
186 case 1 : a+=k[0];
187 final(a,b,c); /* fall through */
188 case 0: /* case 0: nothing left to add */
189 break;
190 }
191 /* report the result */
192 return c;
193 }
194
195
196 /*
197 * --------------------------------------------------------------------
198 * hashword2() -- same as hashword(), but take two seeds and return two
199 * 32-bit values. pc and pb must both be nonnull, and *pc and *pb must
200 * both be initialized with seeds. If you pass in (*pb)==0, the output
201 * (*pc) will be the same as the return value from hashword().
202 * --------------------------------------------------------------------
203 */
hashword2(const uint32_t * k,size_t length,uint32_t * pc,uint32_t * pb)204 void hashword2(
205 const uint32_t *k, /* the key, an array of uint32_t values */
206 size_t length, /* the length of the key, in uint32_ts */
207 uint32_t *pc, /* IN: seed OUT: primary hash value */
208 uint32_t *pb) /* IN: more seed OUT: secondary hash value */
209 {
210 uint32_t a,b,c;
211
212 /* Set up the internal state */
213 a = b = c = 0xdeadbeef + ((uint32_t)(length<<2)) + *pc;
214 c += *pb;
215
216 /* handle most of the key */
217 while (length > 3)
218 {
219 a += k[0];
220 b += k[1];
221 c += k[2];
222 mix(a,b,c);
223 length -= 3;
224 k += 3;
225 }
226
227 /* handle the last 3 uint32_t's */
228 switch(length) /* all the case statements fall through */
229 {
230 case 3 : c+=k[2]; /* fall through */
231 case 2 : b+=k[1]; /* fall through */
232 case 1 : a+=k[0];
233 final(a,b,c); /* fall through */
234 case 0: /* case 0: nothing left to add */
235 break;
236 }
237 /* report the result */
238 *pc=c; *pb=b;
239 }
240
241
242 /*
243 * ----------------------------------------------------------------------------
244 * hashlittle() -- hash a variable-length key into a 32-bit value
245 * k : the key (the unaligned variable-length array of bytes)
246 * length : the length of the key, counting by bytes
247 * initval : can be any 4-byte value
248 * Returns a 32-bit value. Every bit of the key affects every bit of
249 * the return value. Two keys differing by one or two bits will have
250 * totally different hash values.
251 *
252 * The best hash table sizes are powers of 2. There is no need to do
253 * mod a prime (mod is sooo slow!). If you need less than 32 bits,
254 * use a bitmask. For example, if you need only 10 bits, do
255 * h = (h & hashmask(10));
256 * In which case, the hash table should have hashsize(10) elements.
257 *
258 * If you are hashing n strings (uint8_t **)k, do it like this:
259 * for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h);
260 *
261 * By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this
262 * code any way you wish, private, educational, or commercial. It's free.
263 *
264 * Use for hash table lookup, or anything where one collision in 2^^32 is
265 * acceptable. Do NOT use for cryptographic purposes.
266 * ----------------------------------------------------------------------------
267 */
268
hashlittle(const void * key,size_t length,uint32_t initval)269 uint32_t hashlittle(
270 const void *key,
271 size_t length,
272 uint32_t initval)
273 {
274 uint32_t a,b,c; /* internal state */
275 union { const void *ptr; size_t i; } u; /* needed for Mac Powerbook G4 */
276
277 /* Set up the internal state */
278 a = b = c = 0xdeadbeef + ((uint32_t)length) + initval;
279
280 u.ptr = key;
281 if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
282 /* read 32-bit chunks */
283 const uint32_t *k = (const uint32_t *)key;
284 #ifdef VALGRIND
285 const uint8_t *k8;
286 #endif
287
288 /* all but last block: aligned reads and affect 32 bits of (a,b,c) */
289 while (length > 12)
290 {
291 a += k[0];
292 b += k[1];
293 c += k[2];
294 mix(a,b,c);
295 length -= 12;
296 k += 3;
297 }
298
299 /* handle the last (probably partial) block */
300 /*
301 * "k[2]&0xffffff" actually reads beyond the end of the string, but
302 * then masks off the part it's not allowed to read. Because the
303 * string is aligned, the masked-off tail is in the same word as the
304 * rest of the string. Every machine with memory protection I've seen
305 * does it on word boundaries, so is OK with this. But VALGRIND will
306 * still catch it and complain. The masking trick does make the hash
307 * noticably faster for short strings (like English words).
308 */
309 #ifndef VALGRIND
310
311 switch(length)
312 {
313 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
314 case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break;
315 case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break;
316 case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break;
317 case 8 : b+=k[1]; a+=k[0]; break;
318 case 7 : b+=k[1]&0xffffff; a+=k[0]; break;
319 case 6 : b+=k[1]&0xffff; a+=k[0]; break;
320 case 5 : b+=k[1]&0xff; a+=k[0]; break;
321 case 4 : a+=k[0]; break;
322 case 3 : a+=k[0]&0xffffff; break;
323 case 2 : a+=k[0]&0xffff; break;
324 case 1 : a+=k[0]&0xff; break;
325 case 0 : return c; /* zero length strings require no mixing */
326 }
327
328 #else /* make valgrind happy */
329
330 k8 = (const uint8_t *)k;
331 switch(length)
332 {
333 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
334 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
335 case 10: c+=((uint32_t)k8[9])<<8; /* fall through */
336 case 9 : c+=k8[8]; /* fall through */
337 case 8 : b+=k[1]; a+=k[0]; break;
338 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
339 case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */
340 case 5 : b+=k8[4]; /* fall through */
341 case 4 : a+=k[0]; break;
342 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
343 case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */
344 case 1 : a+=k8[0]; break;
345 case 0 : return c;
346 }
347
348 #endif /* !valgrind */
349
350 } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
351 /* read 16-bit chunks */
352 const uint16_t *k = (const uint16_t *)key;
353 const uint8_t *k8;
354
355 /* all but last block: aligned reads and different mixing */
356 while (length > 12)
357 {
358 a += k[0] + (((uint32_t)k[1])<<16);
359 b += k[2] + (((uint32_t)k[3])<<16);
360 c += k[4] + (((uint32_t)k[5])<<16);
361 mix(a,b,c);
362 length -= 12;
363 k += 6;
364 }
365
366 /* handle the last (probably partial) block */
367 k8 = (const uint8_t *)k;
368 switch(length)
369 {
370 case 12: c+=k[4]+(((uint32_t)k[5])<<16);
371 b+=k[2]+(((uint32_t)k[3])<<16);
372 a+=k[0]+(((uint32_t)k[1])<<16);
373 break;
374 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
375 case 10: c+=k[4];
376 b+=k[2]+(((uint32_t)k[3])<<16);
377 a+=k[0]+(((uint32_t)k[1])<<16);
378 break;
379 case 9 : c+=k8[8]; /* fall through */
380 case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
381 a+=k[0]+(((uint32_t)k[1])<<16);
382 break;
383 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
384 case 6 : b+=k[2];
385 a+=k[0]+(((uint32_t)k[1])<<16);
386 break;
387 case 5 : b+=k8[4]; /* fall through */
388 case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
389 break;
390 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
391 case 2 : a+=k[0];
392 break;
393 case 1 : a+=k8[0];
394 break;
395 case 0 : return c; /* zero length requires no mixing */
396 }
397
398 } else {
399 /* need to read the key one byte at a time */
400 const uint8_t *k = (const uint8_t *)key;
401
402 /* all but the last block: affect some 32 bits of (a,b,c) */
403 while (length > 12)
404 {
405 a += k[0];
406 a += ((uint32_t)k[1])<<8;
407 a += ((uint32_t)k[2])<<16;
408 a += ((uint32_t)k[3])<<24;
409 b += k[4];
410 b += ((uint32_t)k[5])<<8;
411 b += ((uint32_t)k[6])<<16;
412 b += ((uint32_t)k[7])<<24;
413 c += k[8];
414 c += ((uint32_t)k[9])<<8;
415 c += ((uint32_t)k[10])<<16;
416 c += ((uint32_t)k[11])<<24;
417 mix(a,b,c);
418 length -= 12;
419 k += 12;
420 }
421
422 /* last block: affect all 32 bits of (c) */
423 switch(length) /* all the case statements fall through */
424 {
425 case 12: c+=((uint32_t)k[11])<<24; /* fall through */
426 case 11: c+=((uint32_t)k[10])<<16; /* fall through */
427 case 10: c+=((uint32_t)k[9])<<8; /* fall through */
428 case 9 : c+=k[8]; /* fall through */
429 case 8 : b+=((uint32_t)k[7])<<24; /* fall through */
430 case 7 : b+=((uint32_t)k[6])<<16; /* fall through */
431 case 6 : b+=((uint32_t)k[5])<<8; /* fall through */
432 case 5 : b+=k[4]; /* fall through */
433 case 4 : a+=((uint32_t)k[3])<<24; /* fall through */
434 case 3 : a+=((uint32_t)k[2])<<16; /* fall through */
435 case 2 : a+=((uint32_t)k[1])<<8; /* fall through */
436 case 1 : a+=k[0];
437 break;
438 case 0 : return c;
439 }
440 }
441
442 final(a,b,c);
443 return c;
444 }
445
446
447 /*
448 * hashlittle2: return 2 32-bit hash values
449 *
450 * This is identical to hashlittle(), except it returns two 32-bit hash
451 * values instead of just one. This is good enough for hash table
452 * lookup with 2^^64 buckets, or if you want a second hash if you're not
453 * happy with the first, or if you want a probably-unique 64-bit ID for
454 * the key. *pc is better mixed than *pb, so use *pc first. If you want
455 * a 64-bit value do something like "*pc + (((uint64_t)*pb)<<32)".
456 */
hashlittle2(const void * key,size_t length,uint32_t * pc,uint32_t * pb)457 void hashlittle2(
458 const void *key, /* the key to hash */
459 size_t length, /* length of the key */
460 uint32_t *pc, /* IN: primary initval, OUT: primary hash */
461 uint32_t *pb) /* IN: secondary initval, OUT: secondary hash */
462 {
463 uint32_t a,b,c; /* internal state */
464 union { const void *ptr; size_t i; } u; /* needed for Mac Powerbook G4 */
465
466 /* Set up the internal state */
467 a = b = c = 0xdeadbeef + ((uint32_t)length) + *pc;
468 c += *pb;
469
470 u.ptr = key;
471 if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
472 /* read 32-bit chunks */
473 const uint32_t *k = (const uint32_t *)key;
474 #ifdef VALGRIND
475 const uint8_t *k8;
476 #endif
477
478 /* all but last block: aligned reads and affect 32 bits of (a,b,c) */
479 while (length > 12)
480 {
481 a += k[0];
482 b += k[1];
483 c += k[2];
484 mix(a,b,c);
485 length -= 12;
486 k += 3;
487 }
488
489 /* handle the last (probably partial) block */
490 /*
491 * "k[2]&0xffffff" actually reads beyond the end of the string, but
492 * then masks off the part it's not allowed to read. Because the
493 * string is aligned, the masked-off tail is in the same word as the
494 * rest of the string. Every machine with memory protection I've seen
495 * does it on word boundaries, so is OK with this. But VALGRIND will
496 * still catch it and complain. The masking trick does make the hash
497 * noticably faster for short strings (like English words).
498 */
499 #ifndef VALGRIND
500
501 switch(length)
502 {
503 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
504 case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break;
505 case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break;
506 case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break;
507 case 8 : b+=k[1]; a+=k[0]; break;
508 case 7 : b+=k[1]&0xffffff; a+=k[0]; break;
509 case 6 : b+=k[1]&0xffff; a+=k[0]; break;
510 case 5 : b+=k[1]&0xff; a+=k[0]; break;
511 case 4 : a+=k[0]; break;
512 case 3 : a+=k[0]&0xffffff; break;
513 case 2 : a+=k[0]&0xffff; break;
514 case 1 : a+=k[0]&0xff; break;
515 case 0 : /* zero length strings require no mixing */
516 *pc=c; *pb=b;
517 return;
518 }
519
520 #else /* make valgrind happy */
521
522 k8 = (const uint8_t *)k;
523 switch(length)
524 {
525 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
526 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
527 case 10: c+=((uint32_t)k8[9])<<8; /* fall through */
528 case 9 : c+=k8[8]; /* fall through */
529 case 8 : b+=k[1]; a+=k[0]; break;
530 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
531 case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */
532 case 5 : b+=k8[4]; /* fall through */
533 case 4 : a+=k[0]; break;
534 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
535 case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */
536 case 1 : a+=k8[0]; break;
537 case 0 : /* zero length strings require no mixing */
538 *pc=c; *pb=b;
539 return;
540 }
541
542 #endif /* !VALGRIND */
543
544 } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
545 /* read 16-bit chunks */
546 const uint16_t *k = (const uint16_t *)key;
547 const uint8_t *k8;
548
549 /* all but last block: aligned reads and different mixing */
550 while (length > 12)
551 {
552 a += k[0] + (((uint32_t)k[1])<<16);
553 b += k[2] + (((uint32_t)k[3])<<16);
554 c += k[4] + (((uint32_t)k[5])<<16);
555 mix(a,b,c);
556 length -= 12;
557 k += 6;
558 }
559
560 /* handle the last (probably partial) block */
561 k8 = (const uint8_t *)k;
562 switch(length)
563 {
564 case 12: c+=k[4]+(((uint32_t)k[5])<<16);
565 b+=k[2]+(((uint32_t)k[3])<<16);
566 a+=k[0]+(((uint32_t)k[1])<<16);
567 break;
568 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
569 case 10: c+=k[4];
570 b+=k[2]+(((uint32_t)k[3])<<16);
571 a+=k[0]+(((uint32_t)k[1])<<16);
572 break;
573 case 9 : c+=k8[8]; /* fall through */
574 case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
575 a+=k[0]+(((uint32_t)k[1])<<16);
576 break;
577 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
578 case 6 : b+=k[2];
579 a+=k[0]+(((uint32_t)k[1])<<16);
580 break;
581 case 5 : b+=k8[4]; /* fall through */
582 case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
583 break;
584 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
585 case 2 : a+=k[0];
586 break;
587 case 1 : a+=k8[0];
588 break;
589 case 0 : /* zero length strings require no mixing */
590 *pc=c; *pb=b;
591 return;
592 }
593
594 } else {
595 /* need to read the key one byte at a time */
596 const uint8_t *k = (const uint8_t *)key;
597
598 /* all but the last block: affect some 32 bits of (a,b,c) */
599 while (length > 12)
600 {
601 a += k[0];
602 a += ((uint32_t)k[1])<<8;
603 a += ((uint32_t)k[2])<<16;
604 a += ((uint32_t)k[3])<<24;
605 b += k[4];
606 b += ((uint32_t)k[5])<<8;
607 b += ((uint32_t)k[6])<<16;
608 b += ((uint32_t)k[7])<<24;
609 c += k[8];
610 c += ((uint32_t)k[9])<<8;
611 c += ((uint32_t)k[10])<<16;
612 c += ((uint32_t)k[11])<<24;
613 mix(a,b,c);
614 length -= 12;
615 k += 12;
616 }
617
618 /* last block: affect all 32 bits of (c) */
619 switch(length) /* all the case statements fall through */
620 {
621 case 12: c+=((uint32_t)k[11])<<24; /* fall through */
622 case 11: c+=((uint32_t)k[10])<<16; /* fall through */
623 case 10: c+=((uint32_t)k[9])<<8; /* fall through */
624 case 9 : c+=k[8]; /* fall through */
625 case 8 : b+=((uint32_t)k[7])<<24; /* fall through */
626 case 7 : b+=((uint32_t)k[6])<<16; /* fall through */
627 case 6 : b+=((uint32_t)k[5])<<8; /* fall through */
628 case 5 : b+=k[4]; /* fall through */
629 case 4 : a+=((uint32_t)k[3])<<24; /* fall through */
630 case 3 : a+=((uint32_t)k[2])<<16; /* fall through */
631 case 2 : a+=((uint32_t)k[1])<<8; /* fall through */
632 case 1 : a+=k[0];
633 break;
634 case 0 : /* zero length strings require no mixing */
635 *pc=c; *pb=b;
636 return;
637 }
638 }
639
640 final(a,b,c);
641 *pc=c; *pb=b;
642 }
643
644
645
646 /*
647 * hashbig():
648 * This is the same as hashword() on big-endian machines. It is different
649 * from hashlittle() on all machines. hashbig() takes advantage of
650 * big-endian byte ordering.
651 */
hashbig(const void * key,size_t length,uint32_t initval)652 uint32_t hashbig(const void *key, size_t length, uint32_t initval)
653 {
654 uint32_t a,b,c;
655 /* to cast key to (size_t) happily */
656 union { const void *ptr; size_t i; } u;
657
658 /* Set up the internal state */
659 a = b = c = 0xdeadbeef + ((uint32_t)length) + initval;
660
661 u.ptr = key;
662 if (HASH_BIG_ENDIAN && ((u.i & 0x3) == 0)) {
663 /* read 32-bit chunks */
664 const uint32_t *k = (const uint32_t *)key;
665 #ifdef VALGRIND
666 const uint8_t *k8;
667 #endif
668
669 /* all but last block: aligned reads and affect 32 bits of (a,b,c) */
670 while (length > 12)
671 {
672 a += k[0];
673 b += k[1];
674 c += k[2];
675 mix(a,b,c);
676 length -= 12;
677 k += 3;
678 }
679
680 /* handle the last (probably partial) block */
681 /*
682 * "k[2]<<8" actually reads beyond the end of the string, but
683 * then shifts out the part it's not allowed to read. Because the
684 * string is aligned, the illegal read is in the same word as the
685 * rest of the string. Every machine with memory protection I've seen
686 * does it on word boundaries, so is OK with this. But VALGRIND will
687 * still catch it and complain. The masking trick does make the hash
688 * noticably faster for short strings (like English words).
689 */
690 #ifndef VALGRIND
691
692 switch(length)
693 {
694 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
695 case 11: c+=k[2]&0xffffff00; b+=k[1]; a+=k[0]; break;
696 case 10: c+=k[2]&0xffff0000; b+=k[1]; a+=k[0]; break;
697 case 9 : c+=k[2]&0xff000000; b+=k[1]; a+=k[0]; break;
698 case 8 : b+=k[1]; a+=k[0]; break;
699 case 7 : b+=k[1]&0xffffff00; a+=k[0]; break;
700 case 6 : b+=k[1]&0xffff0000; a+=k[0]; break;
701 case 5 : b+=k[1]&0xff000000; a+=k[0]; break;
702 case 4 : a+=k[0]; break;
703 case 3 : a+=k[0]&0xffffff00; break;
704 case 2 : a+=k[0]&0xffff0000; break;
705 case 1 : a+=k[0]&0xff000000; break;
706 case 0 : return c; /* zero length strings require no mixing */
707 }
708
709 #else /* make valgrind happy */
710
711 k8 = (const uint8_t *)k;
712 switch(length) /* all the case statements fall through */
713 {
714 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
715 case 11: c+=((uint32_t)k8[10])<<8; /* fall through */
716 case 10: c+=((uint32_t)k8[9])<<16; /* fall through */
717 case 9 : c+=((uint32_t)k8[8])<<24; /* fall through */
718 case 8 : b+=k[1]; a+=k[0]; break;
719 case 7 : b+=((uint32_t)k8[6])<<8; /* fall through */
720 case 6 : b+=((uint32_t)k8[5])<<16; /* fall through */
721 case 5 : b+=((uint32_t)k8[4])<<24; /* fall through */
722 case 4 : a+=k[0]; break;
723 case 3 : a+=((uint32_t)k8[2])<<8; /* fall through */
724 case 2 : a+=((uint32_t)k8[1])<<16; /* fall through */
725 case 1 : a+=((uint32_t)k8[0])<<24; break;
726 case 0 : return c;
727 }
728
729 #endif /* !VALGRIND */
730
731 } else {
732 /* need to read the key one byte at a time */
733 const uint8_t *k = (const uint8_t *)key;
734
735 /* all but the last block: affect some 32 bits of (a,b,c) */
736 while (length > 12)
737 {
738 a += ((uint32_t)k[0])<<24;
739 a += ((uint32_t)k[1])<<16;
740 a += ((uint32_t)k[2])<<8;
741 a += ((uint32_t)k[3]);
742 b += ((uint32_t)k[4])<<24;
743 b += ((uint32_t)k[5])<<16;
744 b += ((uint32_t)k[6])<<8;
745 b += ((uint32_t)k[7]);
746 c += ((uint32_t)k[8])<<24;
747 c += ((uint32_t)k[9])<<16;
748 c += ((uint32_t)k[10])<<8;
749 c += ((uint32_t)k[11]);
750 mix(a,b,c);
751 length -= 12;
752 k += 12;
753 }
754
755 /* last block: affect all 32 bits of (c) */
756 switch(length) /* all the case statements fall through */
757 {
758 case 12: c+=k[11]; /* fall through */
759 case 11: c+=((uint32_t)k[10])<<8; /* fall through */
760 case 10: c+=((uint32_t)k[9])<<16; /* fall through */
761 case 9 : c+=((uint32_t)k[8])<<24; /* fall through */
762 case 8 : b+=k[7]; /* fall through */
763 case 7 : b+=((uint32_t)k[6])<<8; /* fall through */
764 case 6 : b+=((uint32_t)k[5])<<16; /* fall through */
765 case 5 : b+=((uint32_t)k[4])<<24; /* fall through */
766 case 4 : a+=k[3]; /* fall through */
767 case 3 : a+=((uint32_t)k[2])<<8; /* fall through */
768 case 2 : a+=((uint32_t)k[1])<<16; /* fall through */
769 case 1 : a+=((uint32_t)k[0])<<24;
770 break;
771 case 0 : return c;
772 }
773 }
774
775 final(a,b,c);
776 return c;
777 }
778
779
hashbig2(const void * key,size_t length,uint32_t * pc,uint32_t * pb)780 void hashbig2(
781 const void *key,
782 size_t length,
783 uint32_t *pc,
784 uint32_t *pb)
785 {
786 uint32_t a,b,c;
787 /* to cast key to (size_t) happily */
788 union { const void *ptr; size_t i; } u;
789
790 /* Set up the internal state */
791 a = b = c = 0xdeadbeef + ((uint32_t)length) + *pc;
792 c += *pb;
793
794 u.ptr = key;
795 if (HASH_BIG_ENDIAN && ((u.i & 0x3) == 0)) {
796 /* read 32-bit chunks */
797 const uint32_t *k = (const uint32_t *)key;
798 #ifdef VALGRIND
799 const uint8_t *k8;
800 #endif
801
802 /* all but last block: aligned reads and affect 32 bits of (a,b,c) */
803 while (length > 12)
804 {
805 a += k[0];
806 b += k[1];
807 c += k[2];
808 mix(a,b,c);
809 length -= 12;
810 k += 3;
811 }
812
813 /* handle the last (probably partial) block */
814 /*
815 * "k[2]<<8" actually reads beyond the end of the string, but
816 * then shifts out the part it's not allowed to read. Because the
817 * string is aligned, the illegal read is in the same word as the
818 * rest of the string. Every machine with memory protection I've seen
819 * does it on word boundaries, so is OK with this. But VALGRIND will
820 * still catch it and complain. The masking trick does make the hash
821 * noticably faster for short strings (like English words).
822 */
823 #ifndef VALGRIND
824
825 switch(length)
826 {
827 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
828 case 11: c+=k[2]&0xffffff00; b+=k[1]; a+=k[0]; break;
829 case 10: c+=k[2]&0xffff0000; b+=k[1]; a+=k[0]; break;
830 case 9 : c+=k[2]&0xff000000; b+=k[1]; a+=k[0]; break;
831 case 8 : b+=k[1]; a+=k[0]; break;
832 case 7 : b+=k[1]&0xffffff00; a+=k[0]; break;
833 case 6 : b+=k[1]&0xffff0000; a+=k[0]; break;
834 case 5 : b+=k[1]&0xff000000; a+=k[0]; break;
835 case 4 : a+=k[0]; break;
836 case 3 : a+=k[0]&0xffffff00; break;
837 case 2 : a+=k[0]&0xffff0000; break;
838 case 1 : a+=k[0]&0xff000000; break;
839 case 0 : /* zero length strings require no mixing */
840 *pc=c; *pb=b;
841 return;
842 }
843
844 #else /* make valgrind happy */
845
846 k8 = (const uint8_t *)k;
847 switch(length) /* all the case statements fall through */
848 {
849 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
850 case 11: c+=((uint32_t)k8[10])<<8; /* fall through */
851 case 10: c+=((uint32_t)k8[9])<<16; /* fall through */
852 case 9 : c+=((uint32_t)k8[8])<<24; /* fall through */
853 case 8 : b+=k[1]; a+=k[0]; break;
854 case 7 : b+=((uint32_t)k8[6])<<8; /* fall through */
855 case 6 : b+=((uint32_t)k8[5])<<16; /* fall through */
856 case 5 : b+=((uint32_t)k8[4])<<24; /* fall through */
857 case 4 : a+=k[0]; break;
858 case 3 : a+=((uint32_t)k8[2])<<8; /* fall through */
859 case 2 : a+=((uint32_t)k8[1])<<16; /* fall through */
860 case 1 : a+=((uint32_t)k8[0])<<24; break;
861 case 0 :
862 *pc=c; *pb=b;
863 return;
864 }
865
866 #endif /* !VALGRIND */
867
868 } else {
869 /* need to read the key one byte at a time */
870 const uint8_t *k = (const uint8_t *)key;
871
872 /* all but the last block: affect some 32 bits of (a,b,c) */
873 while (length > 12)
874 {
875 a += ((uint32_t)k[0])<<24;
876 a += ((uint32_t)k[1])<<16;
877 a += ((uint32_t)k[2])<<8;
878 a += ((uint32_t)k[3]);
879 b += ((uint32_t)k[4])<<24;
880 b += ((uint32_t)k[5])<<16;
881 b += ((uint32_t)k[6])<<8;
882 b += ((uint32_t)k[7]);
883 c += ((uint32_t)k[8])<<24;
884 c += ((uint32_t)k[9])<<16;
885 c += ((uint32_t)k[10])<<8;
886 c += ((uint32_t)k[11]);
887 mix(a,b,c);
888 length -= 12;
889 k += 12;
890 }
891
892 /* last block: affect all 32 bits of (c) */
893 switch(length) /* all the case statements fall through */
894 {
895 case 12: c+=k[11]; /* fall through */
896 case 11: c+=((uint32_t)k[10])<<8; /* fall through */
897 case 10: c+=((uint32_t)k[9])<<16; /* fall through */
898 case 9 : c+=((uint32_t)k[8])<<24; /* fall through */
899 case 8 : b+=k[7]; /* fall through */
900 case 7 : b+=((uint32_t)k[6])<<8; /* fall through */
901 case 6 : b+=((uint32_t)k[5])<<16; /* fall through */
902 case 5 : b+=((uint32_t)k[4])<<24; /* fall through */
903 case 4 : a+=k[3]; /* fall through */
904 case 3 : a+=((uint32_t)k[2])<<8; /* fall through */
905 case 2 : a+=((uint32_t)k[1])<<16; /* fall through */
906 case 1 : a+=((uint32_t)k[0])<<24;
907 break;
908 case 0 :
909 *pc=c; *pb=b;
910 return;
911 }
912 }
913
914 final(a,b,c);
915 *pc=c; *pb=b;
916 }
917
918
919 #if SELF_TEST
920
921 /* used for timings */
driver1(void)922 static void driver1(void)
923 {
924 uint8_t buf[256];
925 uint32_t i;
926 uint32_t h=0;
927 time_t a,z;
928
929 time(&a);
930 for (i=0; i<256; ++i) buf[i] = 'x';
931 for (i=0; i<1; ++i)
932 {
933 h = hashlittle(&buf[0],1,h);
934 }
935 time(&z);
936 if (z-a > 0)
937 printf("time %d %.8x\n", (int)z-a, h);
938 }
939
940
941 /* check that every input bit changes every output bit half the time */
942 #define HASHSTATE 1
943 #define HASHLEN 1
944 #define MAXPAIR 60
945 #define MAXLEN 70
driver2(void)946 static void driver2(void)
947 {
948 uint8_t qa[MAXLEN+1], qb[MAXLEN+2], *a = &qa[0], *b = &qb[1];
949 uint32_t c[HASHSTATE], d[HASHSTATE], i=0, j=0, k, l, m=0, z;
950 uint32_t e[HASHSTATE],f[HASHSTATE],g[HASHSTATE],h[HASHSTATE];
951 uint32_t x[HASHSTATE],y[HASHSTATE];
952 uint32_t hlen;
953
954 printf("No more than %d trials should ever be needed \n",MAXPAIR/2);
955 for (hlen=0; hlen < MAXLEN; ++hlen)
956 {
957 z=0;
958 for (i=0; i<hlen; ++i) /* for each input byte, */
959 {
960 for (j=0; j<8; ++j) /* for each input bit, */
961 {
962 for (m=1; m<8; ++m) /* for serveral possible initvals, */
963 {
964 for (l=0; l<HASHSTATE; ++l)
965 e[l]=f[l]=g[l]=h[l]=x[l]=y[l]=~((uint32_t)0);
966
967 /* check that every output bit is affected by that
968 * input bit */
969 for (k=0; k<MAXPAIR; k+=2)
970 {
971 uint32_t finished=1;
972 /* keys have one bit different */
973 for (l=0; l<hlen+1; ++l) {a[l] = b[l] = (uint8_t)0;}
974 /* have a and b be two keys differing in only one bit */
975 a[i] ^= (k<<j);
976 a[i] ^= (k>>(8-j));
977 c[0] = hashlittle(a, hlen, m);
978 b[i] ^= ((k+1)<<j);
979 b[i] ^= ((k+1)>>(8-j));
980 d[0] = hashlittle(b, hlen, m);
981 /* check every bit is 1, 0, set, and not set
982 * at least once */
983 for (l=0; l<HASHSTATE; ++l)
984 {
985 e[l] &= (c[l]^d[l]);
986 f[l] &= ~(c[l]^d[l]);
987 g[l] &= c[l];
988 h[l] &= ~c[l];
989 x[l] &= d[l];
990 y[l] &= ~d[l];
991 if (e[l]|f[l]|g[l]|h[l]|x[l]|y[l]) finished=0;
992 }
993 if (finished) break;
994 }
995 if (k>z) z=k;
996 if (k==MAXPAIR)
997 {
998 printf("Some bit didn't change: ");
999 printf("%.8x %.8x %.8x %.8x %.8x %.8x ",
1000 e[0],f[0],g[0],h[0],x[0],y[0]);
1001 printf("i %d j %d m %d len %d\n", i, j, m, hlen);
1002 }
1003 if (z==MAXPAIR) goto done;
1004 }
1005 }
1006 }
1007 done:
1008 if (z < MAXPAIR)
1009 {
1010 printf("Mix success %2d bytes %2d initvals ",i,m);
1011 printf("required %d trials\n", z/2);
1012 }
1013 }
1014 printf("\n");
1015 }
1016
1017 /* Check for reading beyond the end of the buffer and alignment problems */
driver3(void)1018 static void driver3(void)
1019 {
1020 #define GOOD_MEN \
1021 "This is the time for all good men to come to the aid of their country..."
1022
1023 uint8_t buf[MAXLEN+20], *b;
1024 uint32_t len;
1025 uint8_t q[] = GOOD_MEN;
1026 uint32_t h;
1027 uint8_t qq[] = "x" GOOD_MEN;
1028 uint32_t i;
1029 uint8_t qqq[] = "xx" GOOD_MEN;
1030 uint32_t j;
1031 uint8_t qqqq[] = "xxx" GOOD_MEN;
1032 uint32_t ref,x,y;
1033 uint8_t *p;
1034
1035 printf("Endianness. These lines should all be the same"
1036 " (for values filled in):\n");
1037 printf("%.8x "
1038 "%.8x "
1039 "%.8x\n",
1040 hashword((const uint32_t *)q, (sizeof(q)-1)/4, 13),
1041 hashword((const uint32_t *)q, (sizeof(q)-5)/4, 13),
1042 hashword((const uint32_t *)q, (sizeof(q)-9)/4, 13));
1043 p = q;
1044 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
1045 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13),
1046 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13),
1047 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13),
1048 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13),
1049 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13),
1050 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13));
1051 p = &qq[1];
1052 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
1053 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13),
1054 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13),
1055 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13),
1056 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13),
1057 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13),
1058 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13));
1059 p = &qqq[2];
1060 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
1061 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13),
1062 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13),
1063 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13),
1064 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13),
1065 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13),
1066 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13));
1067 p = &qqqq[3];
1068 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
1069 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13),
1070 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13),
1071 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13),
1072 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13),
1073 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13),
1074 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13));
1075 printf("\n");
1076
1077 /* check that hashlittle2 and hashlittle produce the same results */
1078 i=47; j=0;
1079 hashlittle2(q, sizeof(q), &i, &j);
1080 if (hashlittle(q, sizeof(q), 47) != i)
1081 printf("hashlittle2 and hashlittle mismatch\n");
1082
1083 /* check that hashword2 and hashword produce the same results */
1084 len = 0xdeadbeef;
1085 i=47, j=0;
1086 hashword2(&len, 1, &i, &j);
1087 if (hashword(&len, 1, 47) != i)
1088 printf("hashword2 and hashword mismatch %x %x\n",
1089 i, hashword(&len, 1, 47));
1090
1091 /* check hashlittle doesn't read before or after the ends of the string */
1092 for (h=0, b=buf+1; h<8; ++h, ++b)
1093 {
1094 for (i=0; i<MAXLEN; ++i)
1095 {
1096 len = i;
1097 for (j=0; j<i; ++j) *(b+j)=0;
1098
1099 /* these should all be equal */
1100 ref = hashlittle(b, len, (uint32_t)1);
1101 *(b+i)=(uint8_t)~0;
1102 *(b-1)=(uint8_t)~0;
1103 x = hashlittle(b, len, (uint32_t)1);
1104 y = hashlittle(b, len, (uint32_t)1);
1105 if ((ref != x) || (ref != y))
1106 {
1107 printf("alignment error: %.8x %.8x %.8x %d %d\n",ref,x,y,
1108 h, i);
1109 }
1110 }
1111 }
1112 }
1113
1114
1115 /* check for problems with nulls */
driver4(void)1116 static void driver4(void)
1117 {
1118 uint8_t buf[1];
1119 uint32_t h,i,state[HASHSTATE];
1120
1121
1122 buf[0] = ~0;
1123 for (i=0; i<HASHSTATE; ++i) state[i] = 1;
1124 printf("These should all be different\n");
1125 for (i=0, h=0; i<8; ++i)
1126 {
1127 h = hashlittle(buf, 0, h);
1128 printf("%2" PRIu32 " 0-byte strings, hash is %.8x\n", i, h);
1129 }
1130 }
1131
1132
driver5(void)1133 static void driver5(void)
1134 {
1135 uint32_t b,c;
1136 b=0, c=0, hashlittle2("", 0, &c, &b);
1137 printf("hash is %.8lx %.8lx\n", c, b); /* deadbeef deadbeef */
1138 b=0xdeadbeef, c=0, hashlittle2("", 0, &c, &b);
1139 printf("hash is %.8lx %.8lx\n", c, b); /* bd5b7dde deadbeef */
1140 b=0xdeadbeef, c=0xdeadbeef, hashlittle2("", 0, &c, &b);
1141 printf("hash is %.8lx %.8lx\n", c, b); /* 9c093ccd bd5b7dde */
1142 b=0, c=0, hashlittle2("Four score and seven years ago", 30, &c, &b);
1143 printf("hash is %.8lx %.8lx\n", c, b); /* 17770551 ce7226e6 */
1144 b=1, c=0, hashlittle2("Four score and seven years ago", 30, &c, &b);
1145 printf("hash is %.8lx %.8lx\n", c, b); /* e3607cae bd371de4 */
1146 b=0, c=1, hashlittle2("Four score and seven years ago", 30, &c, &b);
1147 printf("hash is %.8lx %.8lx\n", c, b); /* cd628161 6cbea4b3 */
1148 c = hashlittle("Four score and seven years ago", 30, 0);
1149 printf("hash is %.8lx\n", c); /* 17770551 */
1150 c = hashlittle("Four score and seven years ago", 30, 1);
1151 printf("hash is %.8lx\n", c); /* cd628161 */
1152 }
1153
1154
main()1155 int main()
1156 {
1157 driver1(); /* test that the key is hashed: used for timings */
1158 driver2(); /* test that whole key is hashed thoroughly */
1159 driver3(); /* test that nothing but the key is hashed */
1160 driver4(); /* test hashing multiple buffers (all buffers are null) */
1161 driver5(); /* test the hash against known vectors */
1162 return 1;
1163 }
1164
1165 #endif /* SELF_TEST */
1166